Increases in PPARγ posttranslational phosphorylation at serine residues induced by various kinases such as CDK5, extracellular signal-regulated kinase-1/2 and c-Jun N-terminal kinase were reported to be involved in the pathogenesis of insulin resistance, inflammation and obesity [21, 39, 40]. Here, MAPK3 is linked to obesity due to melanocortin 4 receptor deficiency.